This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this experiment is to determine whether pancreatic iron, liver iron, or both predict insulin resistance and impaired islet cell function in thalassemia major patients. To address these aims, this experiment will ask patients to undergo MRI liver and pancreatic iron assessment (or use values from their clinical scans) and to participate in either an oral glucose tolerance test or single fasting glucose assessment. The goal is to improve preclinical recognition of diabetes in iron overloaded patients.